It is the aim of most commercial milling operations to maximize the value obtained from felled trees (stems). At present, this function is carried out by experienced forestry workers known as "logmakers" whose job it is to evaluate where each stem should be sawn so that the resulting logs match required market specifications and are produced according to maximum value specifications. More recently, the tools of the logmaker have included a tape measure and sometimes a separate calliper to determine log lengths and diameters. The logmaker marks the stem at appropriate positions so that a saw operator may saw the stems into lengths which have substantially the desired parameters.
A current aid to some logmakers has been the introduction of a computer based optimisation system which is currently used as an audit and/or educational tool. By manually recording information about the quality and profile (length, diameters and curvature) of the stem at selected positions, and then entering this information into a software program, the optimum cutting positions on any stem can be established which are then compared to positions evaluated by the human logmaker. The human logmaker may then be given advice on how to improve his or her skill. At present, the computer executing the optimisation program is usually not readily accessible by the logmaker. In order for the system to be used, measurements must be recorded in the field (usually on paper) and then later entered into the optimization program which is frequently available only on a remote computer. Once the program has determined the cutting positions, by returning to the logging site the human logmaker may be evaluated and given advice. This process is time consuming and laborious.
It is therefore an object of the present invention to provide apparatus for determining cut positions in stems which goes some way towards overcoming the above disadvantages or which will at least provide the industry with a useful choice.